1. Field of the Invention
This invention relates to a seal construction of a connector, and more particularly to a seal construction of a relay connector for an automatic transmission.
2. Related art
A conventional art technique will be briefly described with reference to FIGS. 5 and 6.
FIG. 5 is a cross-sectional view of a conventional relay connector for an automatic transmission which connector has the function of preventing oil from leaking from an oil case to the exterior through a gap in a conductor portion (wire harness) of a cable.
A relay connector 51 is mounted in a through hole 53, formed through a wall 52 of an oil case of an automatic transmission through an O-ring 55, fitted in a groove 54 formed in an outer peripheral surface of the connector, and a flange 56. With respect to a seal construction of this relay connector, a partition wall 58 is formed within a hollow connector housing 57 in integral relation thereto, and is disposed perpendicularly to an axis C of the connector, and a plurality of terminals 59 (for transmitting electrical signals) are insert molded in the partition wall 58, and extend in the direction of the axis C of the connector housing 57 such that these terminals 59 are exposed to a gas phase side and an oil phase side. The gas phase-side chamber is divided into two regions A and B by a separation wall 70 which is disposed parallel to the axis C of the connector, and has a gouging prevention function.
In this relay connector 51, when the temperature of the oil phase side becomes high, the degree of intimate contact between the connector housing 57 and the electric terminals 59 is lowered because of the difference in thermal expansion coefficient between the two, which leads to a possibility that the oil leaks from the oil phase side to the gas phase side. Therefore, a filling material 60a, 60b (see FIG. 6), such as an epoxy resin, is filled in the gas phase-side chamber.
FIG. 6 is a cross-sectional view showing only the gas phase side, and showing a condition in which the filling material 60a, 60b, filled therein, is completely solidified.
However, in the above conventional seal construction of the relay connector 51 in which the plurality of resin-filling regions, in which the plurality of terminals are arranged, are separated from each other by the separation wall, a width Wa of the region A of the chamber in the relay connector 51 is larger than a width Wb of the region B (Wa&gt;Wb), and therefore the region A and the region B are different in cross-sectional area from each other. Namely, if the resin-filling regions A and B have the same filling height, these regions are different in volume.
Usually, an epoxy resin, silicone or the like, used as the filling material 60a, 60b, has a high viscosity, and therefore in the filling operation, much time is required for the filling of the filling material, so that the filling material is solidified before it is filled uniformly over the entire area.
If the filling regions are different in cross-sectional area (volume), the conditions of the solidified filling material in the two regions are different from each other, and the filling material flows at higher speed (that is, at higher filling rate) in the larger region A than in the narrower region B, and is solidified earlier. Therefore, the height of the filled resin in the narrower region B, in which the filling material is filled at lower speed, is larger than that in the larger region A. As a result, the excess filling material adheres in an irregular manner to the terminals and seal surfaces and so on in the narrower region B.
Therefore, the reliability of the connector is lowered by the degraded electrical performance of the terminals, and in addition, the filling material is wasted.